Method of making printing ribbon spool

ABSTRACT

A method of making a printing ribbon spool is disclosed for maintaining the original print-out density or consistency of a printing ribbon by contact between a pad on the spool and a side edge of the ribbon. Ink is communicated to the pad from a sealed reservoir by way of a wick which communicates with the reservoir through a hole substantially smaller in diameter than the normal uncompressed diameter of the wick.

Ploeger, Jr. et al.

[ June 3, 1975 [54] METHOD OF MAKING PRINTING RIBBON 1,953,881 4/1934Hanable 197/171 SPOOL 2,005,503 6/1935 PCltOn 197/171 2,038,706 4/1936 Bk 197 171 [75] Inventors: Walter Ploeger, Jr., North Bellmore, 2,549,194 1951 H221??? 11712 R N.Y.; John W. H. Bishop, Montreal, 2,549,5616/1952 Knight 197/171 Quebec, Canada 2,644,766 7/1953 Levine 117/2 R2,667,257 1 1954 H rtad 197 Asslgneel Controlled Printout Devices,2,724,489 1111955 Fi:1ds.. 197/111 New York, NY. 2,869,706 1 1959 Bishop197/171 3,095,328 6/1963 Tanchuk 118/268 [22] 1973 3,241,522 3/1966Knight 197/171 21 A 1 N 415,579 3,819,026 6/1974 Ploeger et a1 197/171Related Application Data Primary Examiner-Michael Sofocleous S81. N0.195,710, NOV. 4, 1971, Pat. NO. Attorney Agent or Firm-Seidel, Gonda &Goldhammer U-S. 51 Int. Cl B4lj 31/14 A method a prinfiflg [58] Field ofSearch U 197/171, 175; 1 17/2 R7 closed for maintain ng the or1g1nalprint-out density or 117 12; 118/264, 267, 268 conslstency of a prlntlngrlbbon by contact between a 'pad on the spool and a side edge of theribbon. Ink is communicated to the ad from a sealed reservoir b [56]References Cited f k h p t th way 0 a wrc w 1c communica es w1 ereservo1r UNITED STATES PATENTS through a hole substantially smaller indiameter than 1 g a the normal uncompressed diameter of the wick. 0 ge1,612,772 12/1926 Storck 118/268 5 Claims, 4 Drawing Figures 22 p 1 22/6 l I v I (A 1 y I 1 ,5 1 1 {A f /l a I] L l 20 1 t I J 1 1 v I 1\( llI] g u f /Z 1 6 K L l l I I *1 1 k :1

METHOD OF MAKING PRINTING RIBBON SPOOL This application is a division ofcopending application Ser. No. 195,710, filed Nov. 4, 1971 and now US.Pat. No. 3,819,026.

The present invention is directed to a method of making a printed ribbonspool whereby a printing ribbon wound around the spool is replenishedwith ink to maintain consistency of ink density. The present inventionis particularly adapted for use in connection with Teletype ribbons.Teletype or other slave type machine ribbons have a useful life of about24 to 48 hours. Initially, the Teletype ribbons print too dark. Afterabout 24 hours of use, the Teletype ribbons print too lightly and haveto be replaced.

Heretofore, the printing ribbon spools on a Teletype printer such as aTeletype Corporation Model 28 Teletype printer, are carried on avertical ribbon spool post which has a pivotable toggle at the top. Whenthe spool is mounted on the post, the toggle is pivoted from an axialposition to a radial position so that it acts as a stop shoulder againstwhich the upper surface of the spool contacts. However, the platformwhich carries the spool vibrates to a substantial extent,notwithstanding the aforesaid toggle stop shoulder. The spools of thepresent invention use a magnet to prevent such vibration.

The present invention solves the above-mentioned disadvantages inconnection with Teletype printing ribbons and has other advantages. Thepresent invention has a life span of approximately 6 weeks or longerinstead of the usual 24 to 48 hours. At the same time, the presentinvention provides a spooled-ribbon wherein the ribbon writes with aconstant density from the beginning to the end of its life span.Further, the present invention utilizes a printing ribbon which issubstantially shorter than that on a conventional Teletype machine. Aconventional Teletype machine has a ribbon whose length is about 12yards as compared with the present invention wherein the ribbon has alength of about 1 to 2 yards.

In accordance with the present invention, ink is withdrawn from areservoir by capillary action using a wick of compressible materialhaving one end communicating with said reservoir by way of an openingsubstantially smaller in dimensions than the transverse dimensions ofsaid wick in its uncompressed state. Except for said wick opening, thereservoir is hermetically sealed. Ink is transferred from the wick to apad and from the pad to a printing ribbon by contact between the pad andan extreme side edge of the ribbon only during relevant movement betweenthe pad and ribbon.

Spools in accordance with the present invention are preferably utilizedin pairs with each end of a ribbon secured to one of the spools. Theterminal end portion comprising about 2 inches at each end of the ribbonis either of reduced width or ink impermeable so as to prevent inkbuild-up in said terminal portion from which ink is never withdrawnduring operation. It is desirable to prevent ink on said terminalportion from being transmitted to the hub of the spool. A grommet ispreferably secured to each ribbon end portion to effect reversing thespools in a conventional manner on a Teletype printer. While the presentinvention is particularly adapted for use on Teletype printers, it haswide application to other types of printing ribbons in a variety oftypes of printing equipment wherein long life and uniform density ofprinting are desired.

It is an object of the present invention to provide a novel method forreplenishing ink in a printing ribbon as it is wound and/or unwound froma spool by contact between a source of ink and a side edge of the ribbonduring relevant movement between said source and the ribbon.

It is another object of the present invention to provide a method ofreplenishing ink in a printing ribbbon spool having long life, uniformprinting density during its life span, while utilizing a ribbon which issubstantially shorter than those utilized heretofore.

Other objects will appear hereinafter.

For the purpose of illustrating the invention, there is shown in thedrawings a form which is presently preferred; it being understood,however, that this invention is not limited to the precise arrangementsand instrumentalities shown.

FIG. 1 is a perspective view of a pair of spools in accordance with thepresent invention.

FIG. 2 is a sectional view taken along the line 2-2 in FIG. 1, but on anenlarged scale.

FIG. 3 is a sectional view taken along the line 3-3 in FIG. 2, but on anenlarged scale.

FIG. 4 is a partial sectional view, similar to FIG. 2, but showinganother embodiment of the present invention.

Referring to the drawing in detail, wherein like numerals indicate likeelements, there is shown in FIG. 1 a pair of printing ribbon spools inaccordance with the present invention, each designated generally as 10.

The spool 10 has a body which includes a circular hub 12 having aradially outwardly directed flange 14 at one end and a radiallyoutwardly directed flange 16 at its other end. The flanges 14 and 16 arespaced from one another and parallel to one another. However, flange 16has an inturned end 15 projecting toward flange 14. Flanges l4 and 16are of the same diameter. The flange 14 is integral with the side wall19 and flange 16 is integral with stepped side wall 18.

The hub 12 is preferably provided with flats when being utilized on aTeletype printer. These flats are directly opposite one another. One ofthe flats serves to provide an acceptable surface for attachment, in anyconvenient manner such as by ultrasonic welding, to one end of an inkedribbon. The other flat is utilized to provide take-up space for themetal reversing eyelet which effects reversing of the ribbon on theTeletype printer. The terminal end portion of the ribbon constituting alength at least equal to the circumference of the hub 12 is either ofreduced width or rendered ink impregnable, such as by use of an inkimpervious plastic shield, so as to prevent ink from accumulating insaid terminal end portion.

The hub 12 has a third flange 20 which extends radially outwardly. Thelength of flange 20 in a radial direction is substantially less than theradial length of flanges l4 and 16. Further, flange 20 as shown moreclearly in FIG. 2 is substantially closer to flange 16. The radiallength of flange 20 exceeds the radial thickness of ribbon which willaccumulate on a fully wound spool. A highly absorbent annular felt pad22, which is readily deformable and to some extent compressible, issupported by the flange 20 and projects downwardly between the in-turnedend 15 on the flange l6 and the outer periphery of flange 20. Thus, aportion 23 of the felt pad 22 is exposed and faces flange I4.

The spool body includes a core 24 which is hollow and adapted to receivea mounting post. Core 24 has a concentric and enlarged diameter portion26 within which is fixedly secured a driver 28.

. The driver 28 is preferably a plastic annular member impregnated withmagnetizable material. Driver 28 is force-fit or otherwise secured tothe enlarged diameter portion 26. If desired, driver 28 may beadhesively secured to the enlarged diameter portion 26. Driver 28 isprovided with one or more holes 30 to effect rotation of the spool aboutthe longitudinal axis of core 24.

The spool body is preferably made in two pieces from an ink imperviouslightweight material such as a polymer plastic. A suitable polymer forthe body would be Celcon, which is a commercially available highcrystalline acetal copolymer based on trioxane. One body portion iscomprised of the hub 12, flange 14, wall 19, portion 26, and core 24.The other body portion is comprised of wall 18 and flange 16. The sideedge portion of hub 12 adjacent wall 18 is preferably hermeticallysealed thereto in any convenient manner such as by use of ultrasonicwelding, adhesives, and the like. If desired, the core 24 could beextended and similarly sealed to wall 18.

Thus, the spool body includes an annular sealed chamber 33 defined atits inner periphery by core 24 and portion 26. The outer periphery ofthe chamber 33 is defined by the hub 12. Within the sealed chamber 33,there is provided a sealed ink reservoir. In the preferred embodiment,the sealed ink reservoir includes a carrier such as an absorbent,deformable felt pad 34 impregnated with ink.

At least one wick extends from pad 22 to the sealed ink reservoir. Asillustrated, a pair of diametrically opposed wicks 38 and 39 is providedwith each wick in contact with pad 34. Pad 22 partially compresses theexposed portion of the wicks supported by flange 20.

Each of the wicks 38 and 39 extends through a discrete hole 36 in thehub 12. The diameter of the hole 36 is significant in terms of thediameter of the wick. The diameter of hole 36 should be approximately80% of the diameter of the wicks in their uncompressed state. Using awick having a nominal diameter of oneeighth of an inch, optimum resultshave been obtained using holes 36 having a diameter of 0.099 inch.Except for the wick holes, the chamber 33 is hermetically sealed.

With a spool constructed as set forth above, we have observed that theportion of the wicks outside the casing 32 have a gray color indicatingvery little or no ink in the outer peripheral portion of the wick. Anextremely small hole having a diameter of 0.004 inch was drilled throughthe wall 18 and immediately sealed with pressure-sensitive tape. As soonas the hole was uncovered by removing the tape, the exposed portion ofthe wicks immediately took on the color of the ink. Hence, we have foundthat it is important to have an ink reservoir which is hermeticallysealed except for the wick hole.

Each wick has one end communicating with the ink reservoir and its otherend in contact with the felt pad 22. Thus, each wick has a portionextending through a hole 36 in the hub 12 with its adjacent terminal endresting on the flange beneath and in contact with the undersurface ofpad 22.

A ribbon 42 having a length of approximately one to two yards extendsbetween a pair of the spools 10. Each end portion of the ribbon 42 issecured to one of the spools 10 as described above. The width of theribbon 42 is equal to or slightly greater than the distance from theexposed portion 23 of pad 22 to the flange 14. As pointed out above, thelast several inches at each end of the ribbon 42 may be narrower by adistance of approximately one-eighth of an inch so as to avoid contactbetween the terminal end portion of the ribbon and portion 23 of pad 22.Alternatively, the terminal end portions of the ribbon 42 may be encasedin a plastic ink-impervious sleeve. The ribbon 42 is preferably a 5caliber nylon ribbon having a minimum thread count of about 274 threadsper inch. Such a ribbon is conventionally used for printing ribbons oncomputers.

In FIG. 4, there is illustrated a second embodiment of the presentinvention designated generally as 10. The printing ribbon spool 10' isidentical with spool 10 except as will be made clear hereinafter. Thus,in spool 10', the chamber 33 contains a hermetically sealed casing 32filled with ink. Casing 32 has a hole through which wick 38' extends andwhich is of the same dimensions as hole 36. Otherwise, the embodimentsare identical.

The spool 10 may be assembled as follows:

The body may be injection molded in two pieces as described above. Thedriver 28 may be attached in the portion 26 when desired during theinitial assembly or during late stages in the assembly.

Before introducing the reservoir into the spool body, the wicks arethreaded or otherwise forced through the holes 36 until they assume thedisposition shown in FIG. 2, or equivalent disposition such as the wicksextending to the wall 19. Thereafter, the free or exposed end portionsof the wicks may be extended through the holes 36 in the hub 12.

The uninked pad 22 is placed in position overlying the flange 20 withthe inner periphery of pad 22 in contact with the outer periphery of hub12. The impregnated pad 34 is introduced into chamber 33. For ease ofhandling, pad 34 may be encased in a sleeve at one end portion whereinthe sleeve would not contact the wick. Thereafter, the wall 18 isjuxtaposed to the other spool body portion and sealed thereto by the useof ink impervious adhesives or ultrasonic welding. During this step theportions of the wicks on flange 20 and to some extent the pad 22 arecompressed. In this manner, a spool body is produced which cannot bereused after the ink reservoir has been depleted. With the hermeticallysealed spool and reservoir provided in this manner, with no movingparts, there is no occasion for a user to tamper with the contentsthereof.

We do not know and cannot explain how or why the invention works withany degree of certainty. It is our belief that the use of a hole such ashole 36 through which the wick extends is an important feature of theinvention. In this regard, the diameter of hole 36 must be substantiallyless than the diameter of the wick in its uncompressed state. As pointedout above, excellent results have been obtained wherein the diameter ofthe hole 36 is approximately percent of the diameter of the wick in itsuncompressed state.

Test results have indicated that the spooled ribbon of the presentinvention has a leakproof and exceptionally long storage shelf life. Itis believed that the wick does not continuously transfer ink to the padexcept when the pad 22 is transferring ink to the ribbon 42.

When the spool is in use, the ribbon 42 appears to wiggle or flex theexposed portion 23 of pad 22. During winding, the ribbon 42 tends toflex exposed portion 23 of pad 22 radially inwardly. During unwinding,the ribbon 42 flexes portion 23 radially outwardly. It appears that thisaction primes or pumps the flow of ink through the wicks. When the spoolis not in use, the capillary flow of ink along the wicks stops after ashort period of time.

When assembling the spool 10, it is not necessary for pad 22 to bepre-inked. After about 6-8 hours of shelf life, pad 22 will become inkedto a certain point and thereafter absorbs no further ink from the wicks.This seems to indicate that a balance has been achieved. If the newlyassembled spool is put on a machine with pad 22 still dry, the pad 22starts transferring ink to the ribbon in less than 3 hours and will bewetter than the pad of a spool which has been sitting on a shelf for 6-8hours.

During usage, the driver 28 magnetically exerts sufficient force to holdthe spool downwardly so as to avoid the vibration to which such spoolshave been subjected heretofore in certain types of Teletype printers.The minimizing of vibration has a beneficial effect on proper trackingof the ribbon 42 and on the uniformity of the printing. One spool isrotated clockwise by projections entering into the holes 30 on each ofthe drivers, while the other spool is rotated counterclockwise.

During the single pass of the ribbon, ink will be replenished at the topedge of the ribbon 42 twice, that is, once during takeup and once duringpayout. As ink is withdrawn from the area on the ribbon which is hit bythe key, the struck area will replenish itself by drawing throughcapillary action from an adjacent area thereabove. The bottom edgeportion of the ribbon below the key-strike area remains relatively dry.By continuing the feeding of the top area of the ribbon due to contactbetween the side edge of the ribbon 42 and the portion 23 of felt pad22, the area struck by keys on the ribbon 42 will always have a supplyof ink thereabove to draw from.

While the above-described embodiments utilize one or more wicks whichare round, it will be readily apparent that wicks of othercross-sectional configurations may be utilized. If so, the ratio oftransverse dimensions of the wicks and the holes which communicate thewicks with the reservoir should be maintained.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof and,accordingly, reference should be made to the appended claims, ratherthan to the foregoing specification as indicating the scope of theinvention.

We claim:

1. A method of replenishing ink in a printing ribbon comprisingwithdrawing ink from a sealed reservoir by capillary action using a wickof compressible material having one end communicating with saidreservoir by way of an opening smaller in dimensions than the transversedimensions of said wick in its uncompressed state, compressing said wickat said opening, transferring the ink from said reservoir by said wickto a deformable pad, transferring ink from the pad to a printing ribbonby contact between the pad and a side edge of the ribbon, and initiatingsaid transfer of ink from said reservoir to said pad by flexing anexposed portion of said pad.

2. A method in accordance with claim 1 including using first and secondspools with the ribbon partially wound around each spool and having alength of approximately 1 to 2 yards, rotating the first spool in aclockwise direction while rotating the second spool in acounterclockwise direction to effect relative movement between the padon each spool and said ribbon to effect said ink transferring step.

3. A method in accordance with claim 1 including 10- cating thereservoir in the spool hub radially inwardly of said pad.

4. A method in accordance with claim 1 including transferring ink fromsaid reservoir to said pad at two discrete locations on the pad.

5. A method in accordance with claim 1 wherein flexing the exposedportion of said pad includes flexing said pad portion radially inwardlyand radially outwardly during winding and unwinding of said ribbon.

1. A method of replenishing ink in a printing ribbon comprisingwithdrawing ink from a sealed reservoir by capillary action using a wickof compressible material having one end communicating with saidreservoir by way of an opening smaller in dimensions than the transversedimensions of said wick in its uncompressed state, compressing said wickat said opening, transferring the ink from said reservoir by said wickto a deformable pad, transferring ink from the pad to a printing ribbonby contact between the pad and a side edge of the ribbon, and initiatingsaid transfer of ink from said reservoir to said pad by flexing anexposed portion of said pad.
 1. A method of replenishing ink in aprinting ribbon comprising withdrawing ink from a sealed reservoir bycapillary action using a wick of compressible material having one endcommunicating with said reservoir by way of an opening smaller indimensions than the transverse dimensions of said wick in itsuncompressed state, compressing said wick at said opening, transferringthe ink from said reservoir by said wick to a deformable pad,transferring ink from the pad to a printing ribbon by contact betweenthe pad and a side edge of the ribbon, and initiating said transfer ofink from said reservoir to said pad by flexing an exposed portion ofsaid pad.
 2. A method in accordance with claim 1 including using firstand second spools with the ribbon partially wound around each spool andhaving a length of approximately 1 to 2 yards, rotating the first spoolin a clockwise direction while rotating the second spool in acounterclockwise direction to effect relative movement between the padon each spool and said ribbon to effect said ink transferring step.
 3. Amethod in accordance with claim 1 including locating the reservoir inthe spool hub radially inwardly of said pad.
 4. A method in accordancewith claim 1 including transferring ink from said reservoir to said padat two discrete locations on the pad.